1. Field of the Invention
The present invention relates generally to liquid fuel introduction systems. More specifically, the invention is an ultrasonic liquid fuel introduction system which produces ultrasonic waves at select or variable frequencies and voltages for reducing the droplet size of fuel molecules and to minimize gas consumption by improving the air-to-fuel ratio for combustion.
2. Description of Related Art
Numerous liquid fuel introduction system systems have been devised with the application of ultrasonic vibration for intensifying atomization of fuel mixtures. The underlying problem in the conventional ultrasonic liquid fuel introduction systems is the necessity for disposing mechanical elements (i.e. heat exchangers or heating elements, vibrating elements, impact surfaces, etc.) directly within the fluid flow path to effect the intended result. Flow inhibiting mechanical elements have been the major cause for liquid fuel introduction system failure, and/or the limiting factor of effective and efficient performance over the life of the liquid fuel introduction system. Further, access to these elements for repair is nearly impossible and usually requires complete replacement in lieu of rebuilding the respective part. The other limiting factors resulting from disposing the respective elements within the flow path are the effects of flow adhesion (in the form of carbon deposits), dispersion and/or dissolution that directly affect a proper air-to-fuel ratio within a combustion or similar chamber.
Ultrasonic liquid fuel introduction systems suffering these particular problems are described in U.S. and Foreign Patents respectively issued and granted to Fruengel (U.S. Pat. No. 2,908,443), Thatcher (U.S. Pat. No. 3,533,606), Jackson (U.S. Pat. No. 3,857,375), Sata (U.S. Pat. No. 3,860,173), Priegel (U.S. Pat. No. 3,955,545), Asai et al. (U.S. Pat. No. 4,106,459), Csaszar et al. (U.S. Pat. No. 4,401,089), Wong (U.S. Pat. No. 5,140,966), Tsurutani et al. (U.S. Pat. No. 5,179,923), Durr et al. (GB 508,582), Moss (GB 1,138,536), Burkhard et al. (EP 58,343) and Yuuichi (JP 57-153,964).
Other attempts to reduce fuel particle size have included separating and recirculating oversize fuel particles, particularly in spark-ignition engines as described in the U.S. patent issued to Giannotti (U.S. Pat. No. 4,524,748). As described therein, the device utilizes a nested set of venturi channels which separate oversize fuel particles in an air-fuel mixture by recirculating them to the fuel supply system for reinjection and atomization. An array of low loss venturi nozzles with central traps is utilized to inertially separate the oversize particles.
U.S. Pat. No. 4,570,597 issued to Snaper discloses a fluid controlled fuel system that includes a plurality of fluid controls each of which is responsive to a particular engine condition. The fluid controls are disposed in fluid branches to meter fuel flow and are configured in four branches to respond to choke (start), idle, acceleration, and cruise conditions to meter fuel to an ultrasonic atomizing spray. The atomizer includes a transducer coil that wraps around an exterior portion of the fuel injector nozzle along its length to deliver ultrasonic waves at the point of fuel discharge.
U.S. Pat. No. 5,330,100 issued to Malinowski discloses an ultrasonic fuel injector energized by a solenoid coil that causes a sealing shaft to be pulled away from a valve seat, resulting in the release of fuel. A hollow ultrasonic horn actuator assembly has a tapered part and an interior transducer assembly embedded therein. This particular arrangement makes it virtually impossible for a skilled mechanic to access the embedded transducer, in the event of failure.
The utilization of embedded piezoelectric transducers with vibration characteristics can be seen in the U.S. Patents issued to Oomen (U.S. Pat. No. 3,646,413) and Besocke (U.S. Pat. No. 4,100,442), respectively. Other applications include those with disclosures wherein piezoelectric transducers have been used to obtain pressure measurements without ultrasonic signal generation at a select transmission frequency for fuel atomization. These particular features are described in U.S. Patents issued to Wesley (U.S. Pat. No. 4,266,427), Strobel (U.S. Pat. No. 4,767,960), Dooley et al. (U.S. Pat. No. 4,227,402), Paganelli (U.S. Pat. No. 4,645,965), Takeuchi (U.S. Pat. No. 4,898,024), Takeuchi (U.S. Pat. No. 5,101,659) and Schxc3xa4perkxc3x6tter (U.S. Pat. No. 5,380,014).
Japanese Patent No. 58-200,068 discloses an ultrasonic liquid fuel introduction system comprising a uniform air-fuel mixture between two oscillators, and having formed therein a valve with expandable slits for dispersing fuel. That is, a fuel pipe is formed between an inner and outer piezoelectric ceramic oscillator for fuel traversal. A second set of inner and outer piezoelectric oscillators is adjoined by an intermediate air pipe for introducing air. The outer oscillator is activated by rectangular pulses that compress fuel towards and through the valve with expandable slits.
Japanese Patent No. 56-75,949 discloses a pedal activated ultrasonic liquid fuel introduction system with simultaneous activation of a mixing element disposed within the fluid flow path of a venturi. An ultrasonic generator is disposed at the base of a gas tank comprising a substantially stagnant fuel in liquid form. Ultrasonic waves are promulgated through the base of the tank to a surface portion open to a venturi. One of the problems with this system is the magnitude of transmitted frequencies require to atomize the stagnant fuel in pure liquid form.
None of the above inventions and patents, taken either singly or in combination, is seen to describe the instant invention as claimed.
The present invention is an ultrasonic liquid fuel introduction system that generates an ultrasonic wave in injected fuel to reduce fuel droplet size. The system breaks down larger fuel droplets into a distribution of uniformly sized fuel droplets to produce a smoother ignition wavefront in an engine of a vehicle that results in greater fuel efficiency. The resulting combustion of the air-to-fuel mixture within the chamber enables piston movement by a uniformly compressive wavefront.
The ultrasonic wave is produced via at least one piezoelectric transducer. The transducer has first and second electrodes adapted, to receive an input signal of a frequency (predetermined or variable) and voltage that produces vibrations within a combustion chamber, or fuel injection channel, or other fuel distribution channel, respectively. The frequency or range of frequencies of the ultrasonic wave is typically varied and tailored so that the most efficient frequency is matched to the specification of a particular fuel (e.g., gasoline, diesel, etc.).
Accordingly, it is a principal object of the invention to provide an ultrasonic liquid fuel introduction system that directly reduces fuel droplet size as a virtually non-invasive system.
It is another object of the invention to provide an ultrasonic liquid fuel introduction system that minimizes fuel flow disturbances within a fuel chamber.
It is a further object of the invention to provide an ultrasonic liquid fuel introduction system that improves the air-to-fuel ratio for effecting a smooth ignition of fuel introduced to the system.
Still another object of the invention is to provide an ultrasonic liquid fuel introduction system that significantly reduces overall fuel consumption.
It is yet another object of the invention to provide an ultrasonic liquid fuel introduction system that decreases air pollution by reducing the amount of unburned fuel, reducing incomplete combustion by-products released into the atmosphere, and increasing the fuel efficiency of an internal combustion engine.
It is an object of the invention to provide improved elements and arrangements thereof in an apparatus for the purposes described which is inexpensive, dependable and fully effective in accomplishing its intended purposes.
These and other objects of the present invention will become readily apparent upon further review of the following specification and drawings.